1. Field of the Invention
The present invention relates to the field of computer generated images. More particularly, to the scaling of digital images.
2. Art Background
In computer applications, it often is necessary to scale an image. To expand or "stretch" an image, selective pixels are duplicated in the horizontal and/or vertical directions. Similarly, to reduce or "shrink" an image, selected pixels are dropped. However, one undesirable effect is the visual artifacts created. These artifacts result in horizontal and/or vertical bands in the image. In particular, horizontal replication or dropping produces vertical bands, and vertical replication or dropping results in horizontal bands.
Filtering techniques can be used to remove the bands. However, as filtering is computationally intensive, filtering adds substantial overhead to the system.